Adjective.
1. Steak-like. In reference to Steak.
2. Generally a positive comment of approval or recognition.
Steaky is derived from the word steak. Steak being a tasty peice of meat of high quality. Things that are steaky thus possess steak-like qualities without actually having any implied reference to the meat.

A: I just aced the test!
B: Steaky!

A: A love this band, their music is so steaky.
B: Their steakiness is unmatched.

Meat-headed, but generally more intelligent. Someone who is extremely competitive, when it comes to athletics, drinking, and especially athletics while drinking. However, a steaky individual knows more about how to work out effectively, and is usually a harder worker, than someone who is simply a Meat-Head.

"Dude, Billy just chugged a 12-pack of beers in 3 minutes, injected himself with steroids, and did push-ups in the middle of the party until he passed out, all while yelling 'Must get better for next year'! Thats so steaky!"